Rectangular shutter for spotlights



T. HALL 1,767,756

Filed March 2s, 19294 2I sheets-sheet -1 JJ y!"gn (1542 n 5 |NvENToR .Meadow a M 4 BY 7% l ,/LATTORNEL i RECTAGULAR SHUTTER FOR SPOTLIGHTS Jane 24, 1930.

June 24',` 1930.

T. HALL RECTANGULAR SHUTTER FOR SPOTLIGHTS 2 Shouts-Sheet. 2

Filed March ze, 1929,

Patented June 24, 193@ ,UNITED STATES PATENT erica 'rHnonoan HALL, or NEW YORK, N. Y., AssreNoa To HALL a CONNOLLY, INC., or NEW YORK, N. Y., A CORPORATION or NEW Yon-K RECTANGULAR SHUTTER 'FOR SYOTLIGHTS Application filed March 26, 1929. Serial No. 349,931.

This invention relates to projector lamps especially designed ior illuminating either all or a small portion of the stage in. theaters or public halls. lsiore particularly the invention pertains to ameans for varying'the shape and sizeot the projected beam so 'that the lmaximum amount ot light may be thrown upon 'the stage in the desired size,

f shape and location, and the illumination ot other objects, such as the wings or the top of the curtains, avoided. In my prior Patent No. 1,691,475 for Projector lamps, dated November 13, 1928, I have disclosed the employment ot' an iris shutter which is adjusted automatically with. the spread of the beam lso as to make use ot the; maximum amount oi light at all times. In'the present invention I propose to-employ a novel type of shutter in the same combination either in place of or in addition to the iris shutter. j Referring to the drawings in which the preferred form of the invention is shown,

Fig. 1 is a vertical sectional view through the' forward portion of the projector machine showing the shutter mechanisms and Dthe operating means therefor. .i

Fig. 2 is a front elevation oi my rectangular shutter. l

Fig. 3 'is a detail showing the' horizontally movable elements only. s Fig. 4- is a front elevation of my shutter showing how the same is employed with an iris shutter to produce a small spotlight.

Fig. 5 is a similar Viewy showing both shutters wide open.

Fig. 6 is a diagrammatic side elevation* oi a' projector lamp showingI the interconnecting parts between the shutters and the other parts of the optical system.

F 7 is a view showingl the shutters arrangedto throw a rectangular spot of light on the stage rather than a square spot.

Fig. 8 is a detail showing the adjusting handles for the rectangular shutter.

Referring iirst to Figs. 1 and 6, the projector lamp housing is represented at 1in dotted lines in Fig. 1, the lamp mechanism not being shown therein but being illustratcd generallyv at 2 in Fig. 6. As in my prior patentl I prefer to adjust'the position ot the condenser lenses with respect to the source of light 4t for varying the spread of the beam and I' provide means interconnecting the said adjusting means withthe shutters. ris shown, this adjustment is effected Aby handle 5 on shaft 6- which is threaded in a carriage 7 supporting the condenserlens. Said shaft may drive a second shaft 8 through gears 10. Shaft 8 may serve to adjust both the iris shutter I and the slidable shutter S. For the former purpose, a pinion 11 meshes with a rack bar 11.*, which in turn meshes with a gear sector 40, which in turn drives a worm shaft il through pinion l2. For operating the other shutter, shaft 8 is also shown as provided with a pinion @il which meshes with a rack bar 12. Said pinion is shown'as secured to a sleeve 44: splined on shaft 8 and provided at its outer end with lznurled knob 46, for pulling pinion let out of mesh with rackl 12 tor a purpose hereinafter descril'ied.y Said bar is alsoprovided with teeth 13 adjacent its'upper end -meshing with a pinion 14 ona second shaft 15. Said shaft is shown as hollow and through the same extends an innershatt 16. Wormally said'shatts are rotated together, as hereinafter explained, soA that when the handle 8 is turned both the Vshafts 15 and 16 lare turned together, and thismovement is made use of'to operate my novel shutter. For this purpose Ih-ave shown secured to sleeve .l5-,an arm 17 which .is connected through a linl 118 to asecond arm 19 whichmay be in the form of a double bell" crank or T-shaped lever pivotedat 20. Adjacent each side or. said pivot said lever yis slidably lconnected to pins 21-22 secured toslides Z3-2i so that as said lever 19 is turned said slides are moved in Opposite d1- oted at 30.

rections. Each slide is provided with a substantially square aperture 26 so that when the apertures register as shown in Fig. 3 a large square opening is presented, but as the shutters are closed the aperture in this instance is narrowed so as to produce a vertical rectangular slot. Similarly, to the shaft 16 is secured a lever 27 linked by a link 28 to a similar T-shaped lever 29 piv- Said lever, like lever 19, is pinned at opposite ends to two slides 31-32 adjustable vertically in the oommon'frame 32 in which the slides are mounted. It will, therefore, be seen that if the two shafts 20 and 30 are rotated equally, that a square opening of variable size will be produced, which is always maintained with its center at the same point, namely, in the center of the beam.

I provide, however, means for separately adjusting the shaft 15 and 16 so as to vary the shape of the opening as above stated. For this purpose I provide the shaft 16 with a knurled head 33 and also with a toothed pinion 34. Secured to sleeve 15 is an arm 35 having a knob 36 projectingtherefromV in which is threaded a set screw 37. When the set screw does not engage the teeth of pinion 34 ythe shaft 16 may be turned through knob 33 and the sleeve 15 may be independently turned by grasping'the handie 36. Therefore, with this adjustment, any variation vin shape of a Vrectangular spot desired may be secured. lVhen, however, a square spot of variable size is Vdesired or it is desired to adjust the two sets of slides together to produce a variable size rectangular spot without change of shape, the setscrew 37 is screwed down into engagement with the teeth and pinion 34 so that both shafts are turned together. An indicating hand 50 is shown on shaft 16, readable 'on dial 51 on shaft'16 to show the relative setting of the two shafts and hence the shape of the opening in the shutter (Fig. 8).

My shutter may be employed either alone or in conjunction with the present type of iris shutter. When so employed', I prefer to adjust the gear ratio such that the iris shutter has the faster rate of opening. This vresults inproducing on the stagel a round spot of light when the projector is adjusted to give a very small beam, for instance, when throwing a spotlight on just one or two persons on-the stagetsee Fig. 4). As, however, the shutters are opened the iris opensV thefaster so that when the full beam is thrown on the stage it is square or rectangular in section (Fig. 5). By this means a large flood-light is obtained Vand at the same time the light preventedV from striking the top and bottom 'of the stage, thus producing objectionable fringes of light. If, however, it is desired to use the square spot throughout the range of the lamp, this can be done by changing the relative setting of the two telescopic shutters by disengaging pinion 44 and rack bar 12 by pulling out knob 46 adjusting the iris and then engaging the pinion again so that the opening in the square shutter will fall within or be circumscribed by the smallest openthat the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described by invention, what I claim and desire to secure by Letters Patent is:

1. In a projector lamp, a source of light, condenser, and objective lens, a shutter for varying the size of the projected beam comprising a plurality of pairs of rectangularly movable telescopic slides having overlapping apertures therein, means for moving oppositely the members of each pair, and means for moving all pairs simultaneously.

2. In a projector lamp, a source of light, condenser, and objective lens, a shutter for varying the size of theprojected beam comprising a plurality of pairs of rectangularly movable telescopic slides having overlapping apertures therein, means for moving oppositely the members of each pair, and means for moving said pairs at will.

3. In a projector lamp, a source of light, an optical system therefor including a condenser, and objective lens, means yfor varying the beam spread by adjusting the optical system, a shutter comprising a plurality of pairs of telescopic slides having overlapping apertures therein, and means formoving oppositely the members of each pair by the first-named means.

4. In a projector lamp, a plurality of shutters in the pathV of the beam including an iris shutter and a shutter having rectangularly movable slides, and a common means for adjusting both shutters at a Arelative rate so as to form a small round spot and a large rectangular beam. j

5.`In a. projectorlamp, a plurality of shutters in the path of the beam including an iris shutter and a shutter having rect-angularly movable slides, a commonmeans for adjusting both shutters, and means for varying their relative setting to vary the shape of the projected beam for different size openings.

6. In a projector lam a source of light, an optical system therelor including a condenser, and objective lens, means for varying the beam spread by adjusting the optical system, a shutter comprising a plurality of pairs of telescopic slides having overlapping apertures thereln, an iris shutter, and a common means for adjusting both said slides and iris shutter by said first-named means.

In testimony whereof I have affixed my signature.

THEODORE HALL. 

